Circular knitting machine



May 1, R. BUCK CIRCULAR KNITTING MACHINE Filed Jan. 5, 1940 5 Sheets-Sheet 1 Hey .May 1, 1945. R. BUCK CIRCULAR KNITTING MACHINE Filed Jan. 5, 1940 5 Sheets-Sheet 2 /NvEN'r'oR Rber Buck ATTORNEYS.'

` R. BUCK CIRCULAR KNITTiING MACHINE May A1945. I

' Fild Jan. 5. 1940 5 Sheets-Sheet A3 Ey. 5a

l. lu illmlll May l, 1945. R. BUCK CIRCULAR KNITTING MACHINE y Filed Jan. 5, 1940 5 Sheets-Shed 4 GGOOU il u .bill

May l, 1945. R 'BUCK' CIRCULAR KNITTING- MACHINE Filed'Jan. 5, 1940 5 sheets-sheet 5 I /nvenzor' .Y l Robert Buck llllll Ill l Il ll Patented May l, 1945 OFFICE 2,374,924) i CIRCULAR KNrr'rING MACHINE Robert Buck, Rottenburg-on-the-Neckar,` Germany; vested in the Alien Property Custodian Application January 5, 1940, Serial No. $112,595

In Germany June 4, 1938 16 Claims. (C1.` (i6- 8) The invention relates to knitting machines and more particularly to circular knitting machines. l

In circular knitting machines it has already been proposed to actuate the needles singly by means of rotary cam track members, in order to achieve a knitting operation continuously progressing in a circular path. The warp threads or the thread crossings formed thereby are brought into the path of the needles by the uppermost throat of multi-throated sinker bars, said bars having hooks which on downward movement of the bars grip the thread crossings in order to subject them to the shed or loop forming operation. Owing to the presence of the cam means required for the actuation of the sinker bars, the accessibility of the machine and its control by an operator are considerably impaired because the arrangement of the necessarymechanism around the working circumference `of the machine occupies useful space apart from the fact that the mechanism itself is expensive to manufacture. i i

The present invention provides a circular knitting machine in which a sinker wheel is employed, having sinker throats which seize the thread crossings and move them to the downwardly moving needles. The shaft of the sinker Wheel moves Fig; 4b is a plan view of Fig. 4a. Fig. 5 is a partial sectional elevation, on enlarged scale, of a thread ring guide, needle cylinder and needle and illustrates the knitting method of the invention.

Fig. 5a is schematic development similar to Fig. 4a but taken at right angles to the plane of Fig. 5 and shows engagement of the needles with the thread crossings.

Figs. 6 and '7 are side elevations of two forms of needles.

Fig. 8 Iis a schematic development of the needle cam track showing the needles at different levels and in association with the thread crossings.

Fig. 8a is another schematic development showing the needles at diierent levels, the thread crossings and the thread guide Icam construcin a planetary path around the needley cylinder Such constructions embodying the invention` are diagrammatically illustrated in the drawings in which,

Fig. 1 is a partial sectional elevation of one embodiment of the invention andshows a sinker wheel construction and associated thread ring guide means and needle cylinder.

Fig. la is an isometric detail of amodifled sinker wheel and sinker bar construction and shows the relation of the sinker bars and a needle at a thread crossing.

Fig. 2 is a partialplan view of a toothed wheel usable in place of the sinker wheels of Figs. 2 and la.

Fig. 3 is a view similar to Fig. 1 of another form of the invention. y

Fig. 4 is a View similar to Fig. l of a further modification of the invention.

Fig. la is a schematic development taken at right angles to the plane of Fig. 4 and shows engagement of the needles with the thread crossings.

tion of Fig. 4 for displacing the thread crossings. Fig. 9 is a view similar to Fig. 5 and illustrates the knitting method.

Fig. l0 is also a view similar to Fig. 5 to illus- 'trate the knitting method and in addition shows the thread guide cam of Fig. 4.

Fig. l1 is a detail View in elevation of thread tensioningm'eans employed with the invention.

Fig. l2 i5 a sectional View of Fig. 1l.

Fig. 13 is a sectional elevation of the knitting machine.

The upper and lower warp threads fo and Juv pass from the warp bobbins to the guide rings Z0 and lu from which they pass as shown in Fig. l to the machine needles. A thread crossing is indicated at f in Fig. l. A cam track member k rotates in a planetary path around the needle cylinder z which carries the needles n, which cam track member carries a bearing l for a shaft a. The sinker bars p are mounted in radial or tangential slots in a sinker wheel comprising discs` de and do between which they are pressed, lugs s `op the sinker barsserving to anchor the bars` within the sinker wheel. The drive of the sinker wheel may be effected by the construction shown in Fig. 3 wherein a wheel u' is fixed to the shaft a and which meshes with a iiXed toother ring o. The sinker wheel engages either the shanks of the needlesn or ribs st on the cylinder z, and the take place in known manner.

rotate with the wheel but is xed on the sinker wheel shaft bearing as, for example, the bearing Z shown in Fig. l. By this expedient, the sinker hearings in addition to their circular movement may receive simultaneously a radial movement beyond the duration of the insertion of the needle produced by the cam track.

It is to be noted that Fig. la shows on an enlarged scale the manner in which the thread crossings f cooperate with the sinker p as the knitting needles n are lowered. Since the various modicatiolns of the invention, including those to be hereafter described, engage the thread crossings, in a manner similar to that shown in Fig. la, further illustration is omitted.

In the modification shown in Fig. 2, the sinker wheel is replaced by a toothed wheel rz driven ln the same manner as the sinker wheel. In this arrangement, however, there are no sinker bars as shown in Fig. l, but teeth are provided on the circumference, the spacing of which corresponds to that of the thread crossings.

According to another modification, even the teeth of the wheel are eliminated, and the wheel rg as shown in Fig. 3 has its circumference quite smooth. This smooth wheel rg is driven in the same manner as the sinker wheel and the toothed wheel rz.

The use of these different wheels clearly indicates that even in a plural system machine there is always enough space available between'the separate systems to give accessibility and easy supervision of the machine.

Furthermore, in spite of the increased rapidity of operation, there is greater reliability apart from the fact that the novel constructions are essentially simpler to manufacture and therefore cheaper than the previously known arrangements.

A further modification is shown in Fig. 4, in which instead of a driven wheel, a thread guide cam b is employed which may be fixed on the needle cam track member k. This circularly moving member at a certain instant forces or displaces the thread crossings sufficiently far in the radial direction so that they come into the path of the downwardly moving needle hooks whereby the in-drawing of the warp threads can This modication has thefurther advantage over the previous constructions that no drive elements are present or necessary. This results in greater reliability of operation as well as improved accessibility, ease of operation, and-simplicity of manufacture.

. From the foregoing constructions it will be seen that the sinker bars of the sinker wheel, the toothed wheel rz and .smooth wheel rg, also the thread guide cam E, each serve the purpose of forcing the thread crossing in radial direction into the path of the needle hooks, whereupon the needles on their downward movement draw in the new threads required to form the loop or shed. This displacement of the warp threads must naturally be kept as small as possible so that the tendency is to keep the angle of inclination as and a between the upper and lower warp threads, and the vertical needles, Fig. 5, as small as possible.

To assist in achieving this purpose the present invention provides a hook needle, as shown in' the point P (Fig. 5) which point corresponds to the point F shown in Fig. 7, so that the head slides along the thread crossing, due to its curved form, and the thread crossing is thereby displaced slightly in the radial direction, and after leaving the needle head, it returns to its natural position owing to the tension in the thread. In the ensuing downward movement of the needles, the upper warp thread fo is thus located near the needle hooks, while the lower warp thread j, owing to its somewhat greater angle of inclination au, still lies somewhat outside of the needle hook.

It is evident that this type of needle hook is of special importance in the present invention because the pointed upper ends of the needles pass through the diamond-shaped openings formed by the warp threads more easily than when the blunt ended needles, such as shown in Fig. 6, are employed. Therefore, the normal inclination of the strands relative to the vertical can be reduced, thus providing a narrow space and resulting thread span between the thread guide ring and the needle circle. Obviously, the size of the diamond-shaped openings, when looking in the direction of needle movement, grows smaller as the angle of inclination of the warp threads is reduced.

It will be understood that the different devices of Figs. 1 4 for radially displacing the threads, will produce, when used in cooperation with suitable rnodications of the needle drive as well known in the art, diiferent patterns of knitting. These devices are interchangeable whereby when an order of ware of a pattern requiring the use of the sinker wheel of Fig. 1 is completed, and the next order to be made up is for ware of a pattern requiring, say, the toothed wheel device of Fig. 2, the substitution can be readily effected.

There will now be described a further and very important feature relating to this minimum radial displacement of the warp threads at the needles. Fig. 8 shows a formation of the cam track member k, which moves from left to right. The needles n, separately movable in the xed cylinder a. are brought from the base position G into the ejecting position A in order to bring the fabric W (Fig. 9) reliably behind the needle hooks, without requiring the use of any auxiliary means such as sinkers, clamp rings or the like to hold back the fabric. The needles n are not lowered as heretofore in a single stroke, but in two strokes by means of a double stepped cam. The iirst lowering terminates with the needle hooks at the level E1 and at the instant that the fabric W on the needle shanks begins to touch the hook latches, which latches are not yet closed (Fig. 10). Owing to the ensuing downward movement of the needles, the needle hooks draw the thread crossings of the warp threads fo and fu closer, while the thread guide cam b, shown for example in Figs. 8, `8a and 10, eilects a short displacing movement to force the warp threads radially inwardly into the Ineedle hooks, which movement may be produced by the shape and position of the thread guide cam b. The second lowering step now takes place, this step beginning at the instant that the warp threadsor their crossings are moved into the needle hooks and terminating with the needle hooks at the level E2 whereby uniformloops are formed, this loopforming section being designated by A2 in Figs. 8 and 8a. For further details of the thread guide cam b, attention is directed to Figs. 4a and 4b. These figures show the relative positions of the @am b, needle n, threads fe and fu at the needle leVels E1, A2 Hind E2.

In this connection a new featurein loop sinking should be no-ted because whereas in' all other machines with Vseparately movable needles one thread crossing is very slight so that it is practil cally impossible for any oi the threads to get out of place whether by action of the sinker wheel, of the toothed wheel, of the smooth wheel, or of the thread guide cam.

It must also be appreciatedthat the warp formation and the engagement of the thread crossings by the needles is possible, andin known machines takes place without radial displacement mechanism according to the present invention. The presence of this mechanism, however, makes the needle engagement with the thread crossings much more reliable and precise, and enables `the machine to operate at much greater speeds with a substantially greater output. Although the length of radial displacement is verysmall, it is suicient to bring the thread crossing close to the needle and ensure reliable engagement even at high speed of operation, completely suppressing vibration of the threads at the instant of engagement which would be otherwise a serious disturbing factor at high operation speed. The displacement is shown particularly clearly in 10. j

The above mentioned almostl simultaneous loop sinking oi a plurality of loops has a great advantage from the mechanical point of view that the cams for the ejecting and lowering movements of the needles do not have such abruptly varying contour as in known circular knitting machines, whereby a higher speed of operation and a correspondingly greater output can be achieved without the danger of breaking off needle heads, bending cylinder ribs, or injuring needle channels due to excessively abrupt variation in the contour of cams.

In order to get a better understanding oi the operation of the parts disclosed in Fig. 8, attention is again called to Fig, 8a. In this figure,l the needles of course are stationary and the member b moves circumierentially from left to right in the direction of the arrow `along with the cam track. During this movement, the needles n`, shown to the right of the member b, are rst raised from the level E2 to the level G, and then to the highest level A, after which the needles are again lowered to level E1, and finally to the original level E2. l

During the above-mentioned upward move.- ment of the needles from level E2 to level G and nally to level A, the cam shaped hooks penetrate a` diamond-shaped opening in the inclined warp. These diamond-shaped openings are i clearly shown in the left-hand portion of Fig. 8a, but are omitted from the right-hand portion of this iigure for sake of clearness. As heretofore stated. `by providing the inclined angle shaped hooks on the upper ends of needles n, it is possible to reduce the size of the diamond-shaped openings in the warp and still accurately penetrate these openings with the rising needles. By the term reducing the size ofdiamond-shaped openings, is meant that the inclination of the warp is reduced, that is, positioned more nearly vertical.

` the thread crossings;

This `positioning or reduction of the .inclination will reduce the size of the openings when viewed in the direction of travel of the needles.

When` the needles have been raised upwardly through the warp openings in the level A, the member b has movedcircumferentially into the position shown in Fig. 8a, and at this time the needle hooks are located slightly above the member. Upon further movement to the right, the

point IIJ of member b begins to engage the inf clined warped threadsy fe, fu simultaneously with the. lowering of the threads from the levelA to the level E1. Thus, Ait is seen that the thread crossings f `are forced inwardly away from the observer in Figa and beneath the needle hooks, which hooks are lowered into engagement with tinue to lower, the warp is gradually moved fartherinwardly and away from the observer and toward the center of the needle circle, until the innermost point i l of the cam member b engages the warp. At this time, the lowering needle hooks are engaging` the thread crossings f, and are accordingly reducing the vertical depth of the diamond-shaped openings immediately beneath the hooks.

`During this reduction in size of the diamondshaped openings, the needles are substantially in a position for forming the stitches, that is, knitting the engaged crossthreads. In order to accomplish this function, the needles are again lowered from the level E1 to the level E2. i This lowering and knitting takes place while the cam member b moves circumferentially over the distance or through the section A2. \Also, during this knitting or final lowering of the needles, the warp is held in an inward position by the edge portion of the cam member between points l I and l2, all points on said portion being substantially equidistant from the center of the needle cylinder. Attention is also called to the fact that the engaging portion of the cam edge between points H and I2 is substantially parallel to the inclinationof the top ends "of the adjacent needles as viewed in Fig. 8. v

In circular knitting machines for the manufacture of chain knitted goods, in which the knitting operation advances continuously in a circular path, means have already been provided for individually tensioning the threads whereby each warp thread is imparted the necessary tension for .the knitting operation. Owing to the higher speed of operation made possible bythe hereindescribed radial displacements of the thread .y crossings, knownthread tensioning means have be carried out in very much simpler land easier manner than heretofore, whereby greater facility of supervision of the machine results. The novel arrangement also provides more reliable operation because there is also means for equalizing the tension inside the groups themselves since the device controlling the threads of each group can yield not only when the thread travels in a verticaldirection, but also when it travels in a horizontal direction asparticularly illustrated in Figs.

12 and 13. Since each individual group is yield- `As the needle hooks conably mounted inthe manner just described, the whole aggregate can be subjected to a displacement so that a. complete accommodation of the warp threads to the advancing knitting operation is possible. This novel mechanism is shown in Figs. 11 to 13. In Fig. 13 it will be noted that the radial displacement means is omitted for clearness, but it is to be understood that any of the mechanisms for this purpose, as shown in Figs. 1, 2, 3 or 4, is provided to operate on the thread crossings close to the needles n. With special reference to Fig. 13 the thread supply is disclosed as carried on pairs of bobbins S and Su. These bobbins are respectively supported on the brackets to and tu which are carried on conventional gear means Vo and Vu, the latter being rotatably supported by support members Si. The drive means for each gear means Vo and Vu comprise a separate gear which meshes therewith and which is fixed on a drive shaft Vw. This construction permits one or morepairs of bobbins S0 and Su to be carried by the gear means Vo and Vu. The thread from each bobbin is moved into working relation to a needle as the gear means are rotated, it being noted that the knitted pattern is inuenced by the number of threads employed in the knitting process. The warp threads fo and ,fu pass through eye plates ro and ru and combs mo and mu to the guide rings Z0 and Zu from the upper and lower warp bobbins so and su, and are guided to the needles 1i. The number of threads from one and the same warp bobbin may be divided into six, eight, or more groups. Each group, for example of the lower threads, has assigned thereto an eye plate ru, these being designated in Fig. 1v.,

ll rui, rua, and rus. These eye plates r are shown in Fig. 12, for example, as under the iniluence of a helical spring sp to hold the threads fu in properly tensioned condition. The shifting of the eye plates ru transversely of the vertically disposed thread portions provides a further adaptation to the progressive knitting operation and is obtained as shown in Fig. l1 by a loose mounting of a lever of the plate ru in a cross bar B, which also carries the comb mu. The above mentioned yielding of the aggregate in order to permit more perfect adaptation of the thread tension to the continuously progressing knitting operation, is obtained by suitable mounting of the cross bar B in left and right hand levers Hu, which levers rotate about a nxed 'shaft :c supported by a frame member tu.

I claim as my invention:

l. A circular knitting machine with hooked needles, comprising, a stationary cylinder in which said needles are movably mounted` means for guiding warp threads close to the needles to form thread crossings in the paths of the hooks of the needles, a cam member for operating the needles rotatable about said cylinder, and means supported on said cam member for radially displacing the thread crossings into closer proximity to the needles.

2. In a circular knitting machine having hooked needles mounted in a needle circle member and which are reciprocated and Which are adapted to engage warp threads fed to the needles, the combination of means for guiding said threads close to the needles to form thread crossings in the paths of the hooks of the needles, each of said needles during at least'one operating cycle engaging one of said threads, cam means carried by said needles for displacing the thread crossings outwardly from the needle circle as the needles pass upwardly through the warp, and

means for subsequently displacing the thread crossings inwardly into closer proximity to each needle as the needles are lowered toward knitting position.

3. A machine according to claim 2 in which the radial displacing means includes a rotary disc with its periphery cooperating with the thread crossings.

4. A machine according to claim l in which the radial displacing means includes a rotary disc with its periphery cooperating with the thread crossings.

5. A circular knitting machine with hooked needles comprising, a stationary cylinder in which said needles are movably mounted, means for guiding warp threads close to the needles to form thread crossings in the paths of the hooks of the needles, a cam member for operating the needles rotatable about said cylinder, means supported on said cam member for radially displacing the thread crossings into closer proximity to the needles, said means including a rotary disc, and means on the cylinder for rotating the disc about its own axis as said disc rotates in a planetary path around said cylinder.

6. A circular knitting machine with hooked needles comprising, a stationary cylinder in which said needles are movably mounted, means for guiding warp threads close to the needles to form thread crossings in the paths of the hooks of the needles, a cam member for operating the needles rotatable about said cylinder, means supported on said cam member for radially displacing the thread crossings into closer proximity to the needles, said means including a rotary disc and sinker bars movable therein, and means on the cylinder for rotating the disc about its own axis as said disc rotates in a planetary path around said cylinder.

7. A machine according to claim 6 in which the f* sinker bars are movable in the disc by means of a cam and stationary cam track.

8. A circular knitting mechanism with hooked needles comprising, a stationary cylinder in which said needles are movably mounted, means for guiding warp threads close to the needles to form thread crossings in the paths of the hooks of the needles, a cam member for operating the needles rotatable about said cylinder, means supported on said cam member for radially displacing the thread crossings into closer proximity to the needles, said means including a rotary disc with thread engaging teeth on its periphery, and means on the cylinder for rotating the disc about its own axis as said disc rotates in a planetary path around said cylinder.

9. A circular .knitting machine with hooked needles comprising, a stationary cylinder, in which said needles are movably mounted, means for guiding warp threads close tothe needles to form thread crossings in the paths 'of the hooks of the needles, a cam member for operating the needles rotatable about said cylinder, means supported on said cam member for radially displacing the thread crossings into closer proximity to the needles, said means including a thread engaging cam plate. l

l0. A machine according to claim 1 in which the cam member for operating the needles includes a cam track of configuration shaped to retract the needles in two stages with an intermediate pause instant coincident with the instant of radial displacement of the thread crossings.

11. A machine according to claim l in which the cam member for operating the needles includes a cam track of configuration shaped to retract the needles in two stages with an intermediate pause instant coincident with the instant of radial displacement of the thread crossings and in which the portion of the cam track producing the first stage of needle movement terminates at the point corresponding to contact of the ware on the needles with the hooksA thereof but before the shed begins to close.

12. A machine according to claim 1 in which the cam member for operating the needles includes a cam track of conguration shaped to retract the needles in two stages with an intermediate pause instant coincident with the instant of radial displacement of the thread crossings and in which the portion of the cam track producing the first stage of needle movement terminates at the point corresponding to contact of the ware on the needles with the hooks thereof but before the shed begins to close, and in which i the portion of the cam track producing the second each of said needles during at least oneoperat ing cycle engaging one of said threads, means for radially displacing the thread crossings into closer proximity to each needle as it carries out an operating cycle wherein it engages a thread,

and thread tensioning means including a plurality of units each operating upon a group of warp threads and regulatable tension applying devices acting `on each unit, said tensioning means being operable on said threads at the time of radial displacement and also after completed loop formation.

14. A machine according to claim 13 in which each unit is yieldable transversely to the general thread direction thereat, and is also yieldingly adjustable `for automatic equalization of tension diierences of the threads traversing the unit.

15. A machine according to claim 13, in which the thread tensioning units include eye-plates carried by levers, and springs acting on the levers, and in which a plurality of said leversand eyeplates are jointed with provision for limited transverse displacement on a supporting bar capable of pivotal movement in the vgeneral direction of thread travel.

16. In a circular knitting machine having hooked needles mounted in a needle circle member and which are reciprocated and which are adapted to engage warp threads fed to the needles, the combination of means for guiding said threads downwardly and inwardly close to the needles to form thread crossings in the paths of the hooks of the needles, each of said needles during at least one operating cycle engaging one J of said threads, and cam means carried by said needles for displacing the thread crossings out- Wardly from the needle circle as the needles pass upwardly through the warp.

ROBERT BUCK. 

